Ratings & Comments

Indeed. Please see my comments on the Sultan's game page from October 20 and 21.

Thank you for your comment and the discussion.

Indeed. See my comments from October 20 and 21 for the Sultan's game.

I have made an attempt to implement Fischer castling in the Interactive Diagram. There is no special XBetza notation for this; a shuffle game has to be specified with a 'nominal' setup. This setup defines (together with the XBetza normal castling definition) where the king must end up, and what the castling partners are (the corner pieces, which must be of equal type). If such a castling is defined, any shuffle that involves the king will then be restricted to make the king end up between the castling partners, and will activate Fischer castling.

To support the shuffle rules of Capablanca Random Chess I enhanced the Diagram's shuffle feature: An exclamation point before a piece in a shuffle specification now either means that pieces of that type should be equally distributed over square shades, or, when there only is one such piece, that it must remain on the shade it is already on. This way Q and A can be forced on different shades by putting them so in the nominal position, and order an extra shuffle of only Q and A to determine which one goes on which shade. The shuffle specs are thus QA,N!BR!AC!QK.

Initially a Diagram always shows the nominal position; there is no spontaneous shuffle. To shuffle you have to press 'Restart' in the AI control bar.

[Editor's Note: Disabling this diagram to keep it from interfering with the one on the page.]

<script type="text/javascript" src="/membergraphics/MSinteractive-diagrams/betza.js?nocache=true">
</script>
<div class="idiagram">
files=10
ranks=8
promoZone=1
promoChoice=NBRQAC
graphicsDir=/membergraphics/MSelven-chess/
squareSize=35
graphicsType=png
shuffle=QA,N!BR!AC!QK
pawn:P:ifmnDfmWfceF:pawn:a2,b2,c2,d2,e2,f2,g2,h2,i2,j2,,a7,b7,c7,d7,e7,f7,g7,h7,i7,j7
knight:N:N:knight:c1,h1,,c8,h8
bishop:B:B:bishop:d1,g1,,d8,g8
rook:R:R:rook:a1,j1,,a8,j8
queen:Q:Q:queen:e1,,e8
archbishop:A:BN::b1,,b8
chancellor:C:RN:chancellor:i1,,i8
king:K:KisO3:king:f1,,f8
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When castling, the king move four squares toward one of the rooks, and the rook jumps to the other side of the king.

That definitely sounds more sensible. I had to add a special parameter castlingGap to the Interactive Diagram to support the weird way of castling that is described in the text. (I see the Diagram in the article has already been changed to castle in the normal way, though, unlike the one I first published in the comments.)

Umm, I did not even know this rule existed. WinBoard restricts the shuffle only to have the Bishops on different colors. I agree the rule makes no sense. I have also seen descriptions that did not allow the Bishops to be on adjacent squares. (That also seemed to make little sense.)

The Interactive Diagram would have to struggle to enforce this rule, because there is no way to tell it directly that a pair of pieces of different types would have to be placed on different square shades. As a work-around you could 'mark' the shades by piece type, by defining the nominal start position with a back rank RBRBNKNCQA, so that RNQ are on dark squares, and BKCA on light. You can then order a sequence of shuffles, RNQ,BKCA,QA,!BNRKC .

The first shuffle solely serves to put Q on a random dark square, the second to put A on a random light square, and the third then randomly swaps the two. The remaining pieces then have to be shuffled the usual way, i.e. the Bishops would have to go on opposit shades (indicated by the ! prefix).

I guess it would be useful to extend the shuffling capabilities of the Diagram with a prefix to indicate the piece should stay on the same color as it was in the nominal setup. Sy This would be indicated by #, then the shuffle instructions could be K#QC#AR!BN,QA, with a nominal setup where Q and A start on different shades.

The rule of castling is not correct as far as the Rook is concerned. When castling, the king move four squares toward one of the rooks, and the rook jumps to the other side of the king.

This will be corrected in future editions of A World of Chess, by JL.Cazaux and R.Knowlton.

In addition, the name Tressan has to be corrected to Tressau on this page.

The rule of castling is not correct as far as the Rook is concerned. When castling, the king moves three squares when castling short and four when castling long. The rook jumps to the immediate square on the other side of the king.

This will be corrected in future editions of A World of Chess, by JL.Cazaux and R.Knowlton.

But why the limitation to set up queen and archbishop on different coloured squares, when they can change the square colour by moving like rook resp. knight?

Very good, having cleared the cache and deleted the cookies, the AI no longer commits the illegality of not converting the bishop. Now it plays 24 ... Qc4. Continuing the game it developed like this:

1.g3 d5 2.d4 f5 3.Bg2 e6 4.f4 Qb4 5.c3 Qb5 6.Nf2 g6 7.Nd3 a5 8.a4 Qc4 9.Nd2 Qc6 10.Ne5 Qb6 11.b3 Nc6 12.Ndf3 Qd6 13.Ba3 Qd8 14.Bc5 Qa6 15.Qf2 Nxe5 16.Nxe5 b6 17.Ba3 Nf7 18.Nxf7 Bxf7 19.O-O Qf6 20.c4 dxc4 21.Bxa8 Qxa8 22.Ki1 cxb3 23.Rb1 Qd5 24.Rxb3 Qc4 25.Rd3 b5 26.axb5 Qxb5 27.Qa1 i5 28.Rb1 Qd5 29.Bc5 Qa8 30.Qa4 c6 31.Bb6 Bd8 32.Bxd8 Kxd8 33.Rdb3 Qa6 34.Rb6 Qa7 35.Qxc6 h5 36.Qd6 Qd7 37.Rb8#

Thanks for showing me the solution. So when will we see the Interactive Diagram offered on the Google Apps Store?

I've been playing a lot of this game recently (via Ai Ai), partly for my own enjoyment and partly as inspiration for my own 16x16 experiments. There are relatively few modern Chess variants played on 16x16, and for me, this game is the best example thus far.

The variety of pieces presented here is at first intimidating, but one soon realises there is a logic to everything presented here, and shortly thereafter you'll find the piece movements become natural. The balance of the initial position is excellent, with every piece finding its way into the fight without too much awkward development. Games are long -- against AI at 2 minutes/move my games take at least 400 plies, with my longest so far at 695 -- but as a large Shogi variant fanatic this doesn't bother me at all. Throughout those long games one will find drama, excitement, and plentiful opportunities for subtlety and subterfuge.

If I were very picky, I might say that I'd like to see the Rook + Camel/Bishop + Camel compounds in here, which I find really fun on a large board. Also the basic leapers -- Camel, Giraffe, Knight -- feel less impactful in a game this size. Having said that, everything works well together, and I enjoy this game tremendously.

I clarified the ambiguity associated with the interpretation of the double-step rule and also emphasized the identity of the pieces' movement to other hexagonal variants. I will also add extra information, related to this variant in the near future.